Compact constant pressure lubricator for the 20 mm. hs 820 gun system



G. D'ANDREA COMPACT CONSTANT PRESSURE LUBRICATOR FOR May 21, 1968 THE 20MM.HS 820 GUN SYSTEM 3 Sheets-Sheet 1 Filed Dec. 14, 1966 Ti l INVENTOREiuliunu DA'nfl'ren M 8 BY. 8 Z r W M, K E.

I r ATTORNEY G. DANDREA COMPACT CONSTANT PRESSURE LUBRICATOR FOR May 21,1968 THE 20 MM.HS 820 GUN SYSTEM 3 Sheets-Sheet 2 Filed Dec. 14, 1966INVIENTOR 5 1111111110 1] Anfireu.

BY Wain/x -M- v ATTORNEY y 1968 G. DANDREA 3,383,984

COMPACT CONSTANT PRESSURE LUBRICATOR FOR THE 20 MM.HS 820 GUN SYSTEMFiled Dec. 14, 1966 5 Sheets-$heet 3 as 83 loo 96 86 im mm I INVFNTOR51111111110 I] Andrew.

7 I I 8. 0' ATTORNEY United States Patent 3,383,984 COMPACT CONSTANTPRESSURE LUBRICATOR FOR THE 20 MM. HS 820 GUN SYSTEM Giuliano DAndrea,Troy, N.Y., assignor to the United States of America as represented bythe Secretary of the Army Filed Dec. 14, 1966, Ser. No. 601,813 8Claims. (Cl. 89-1) ABSTRACT OF THE DISCLOSURE The cases of cartridgesare lubricated as they are fed into the receiver of an automatic gun bya lubricator having a reservoir for a lubricant with a cooperatingpiston connected to a negator spring for moving the lubricant in thereservoir to an applicator at a constant pressure. The applicator isprovided with a pair of nozzles with cooperating plunger-valvescontactable simultaneously by each of the cases during movement into thereceiver for displacement thereby to apply a specific amount of thelubricant upon the case.

This invention relates to machine guns in which cartridges are fedradially thereinto and it pertains more particularly to a lubricator forapplying a lubricant to the cases of the cartridges while being fed intothe gun.

With some machine guns it is important, for the proper operationthereof, that the cartridge cases be freely extracted from the barrelchamber after firing and therefore lubrication of the case is necessary.Consequently, positive lubrication of the cases is important and it isalso important that the same degree of lubrication be given each of thecases to provide a smooth operation of the gun.

It is therefore the principal object of this invention to provide forsuch machine guns a lubricator which positively lubricates the cartridgecases in all operating conditions and in all attitudes of the guns andwith each cartridge receiving the same degree of lubrication.

It is a further object of this invention to provide such a lubricatorwhich is simple but rugged in construction and is easily serviced.

The specific nature of the invention as well as other objects andadvantages thereof will clearly appear from a description of a preferredembodiment as shown in the accompanying drawings in which:

FIG. 1 is an end view of the lubricator mounted on the feedway housingof a machine gun;

FIG. 2 is an enlarged perspective view showing how the applicator of thelubricator is adjustably mounted on the feedway housing;

FIG. 3 is an elevational view of the lubricator;

FIG. 4 is an enlarged fragmentary cross-section taken along line 44 ofFIG. 1;

FIG. 5 is a fragmentary view similar to FIG. 4 but showing one of thevalve-plungers elevated by contact with a cartridge case to its openposition;

FIG. 6 is a view taken along line 6-6 of FIG. 1;

FIG. 7 is a perspective view of the yoke;

FIG. 8 is an end view of the yoke;

FIG. 9 is view taken along line 9-9 of FIG. 6; and

FIG. 10 is a view taken along line 10-10 of FIG. 5.

Shown in the figures is a machine gun 12 having a receiver 14 and afeeder mechanism 16 for moving cartridges 18, which are linked to form acartridge belt 20, to the gun. Feeder mechanism 16 includes a feedwayhousing 22 for guiding cartridge belt 20 into a feeder 23 on receiver 14where cartridges 18 are stripped from the cartridge belt by conventionalstripper means (not shown) and moved into the receiver. Housing 22includes a base 24 having a pair of longitudinally spaced slideways 26which are of raised ridge-type configuration so as to provide slidingsupport for cartridge belt 20 and position cartridges 18 verticallyduring passage through the housing. A sprocket device 28 is mounted inhousing 22 for engagement with cartridge belt 20 to advance cartridges18 therein into feeder 23.

Mounted on housing 22 is a lubricator 30 for applying a lubricant 32onto cases 34 of cartridges 18 as they are advanced through the housing.Such lubricator 30 includes an applicator 36 and a charger 38 which areboth mounted on the top of housing 22 and arranged, as hereinafterdescribed, to apply a specific amount of lubricant 32 onto cases 34 asthey pass through the housing.

Charger 38 includes a cylinder 40 closed at one end, hereinafterreferred to as the discharge end, by a cap 42 which is provided with aninside recess 44. A piston 46 is slidingly mounted in cylinder 40 toform between such piston and cap 42 a variable reservoir 48 forlubricant 32. Replaceably mounted in cylinder 40 at the discharge endthereof is a spring device 50 which is connected to piston 46 andarranged, as hereinafter described, to draw such piston toward thedischarge end of cylinder 40 at a constant force during displacementthereto as lubricant 32 is discharged from reservoir 48.

Spring device 50 includes a yoke 52 which is essentially cylindrical inconfiguration and is mounted in a mating counterbore section 53 formedat the discharge end of cylinder 40. As shown in FIG. 7, the end of yoke52 which is adjacent cap 42 is recessed to form a well 54 and theremainder of the yoke is bifurcated by a slot 56 which has communicationwith the well and which forms a pair of segmental sections 57.

Extending between sections 57 in vertical relationship, as noted in FIG.6, is a pair of shafts 58 which respectively mount a drum 60. Mounted oneach of the drums 60 is a spring 62 of negator type designed to providea constant force at the free end as the spring returns to its woundcondition on the related drum. Springs 62 are wound on drums 60 so as toconverge as they are unwound, permitting free ends 64 of the springs tobe joined together at 65 to piston 46. Extending longitudinally througheach of the sections 57 is a bore 66 which provides communicationbetween reservoir 48 and recess 44 for passage of lubricant 32 theretowhen piston 46 is displaced toward the discharge end of cylinder 40 byspring device 50 as the amount of lubricant 32 in reservoir 48 isdepleted.

Lubricant 32 is conducted from recess 44 to applicator 36 by means of aconduit 68 and is received by a chamber 70 in the applicator. Fromchamber 70 lubricant 32 is discharged onto cases 34 by means of a pairof nozzles 72 which extend downwardly into housing 22 and arelongitudinally spaced so that both register with one of the cases duringpassage under applicator 36. The flow of lubricant 32 through each ofthe nozzles 72 is controlled by a plunger-valve 74 which isspring-biased to a closed position to block the respective nozzle. Eachof the plungervalves 74 is provided with an axial pin 76 that extendsdownwardly from the respective nozzle 72 so that the end is contactableby cases 34 during passage thereby. The contact of a case 34 with theends of pins 76 cause plunger-valves 74 to be cammingly raised, as shownin FIG. 5, and thereby unseated to permit the flow of lubricant 32 alongclearance channels 78 in nozzles 72 and onto the case.

The amount of lubricant 32 which is applied to case 34 is adjustable bythe addition or removal of shims 80 between applicator 36 and housing22, as shown in FIG. 2, to vary the position of the ends of pins 76relative to slideways 26 and thereby the time during which valveplungers74 are held open by the case and the degree to which they are unseated.

Piston 46 is retracted in cylinder 40 away from cap 42, so thatreservoir 48 may be filled with lubricant 32 through a port 82 in thedischarge end of the cylinder, by means of a cable device 83. Such cabledevice 83 includes a cable 84 which is attached at one end to piston 46and at the other end to a slider 86 which is slidingly disposed in ahousing 88 mounted longitudinally on the outside of cylinder 40. Cable84 passes over a pair of pulleys 90 mounted on cylinder 40 at the endthereof opposite the discharge end to facilitate the retraction ofpiston 46 by slider 86.

Slider 86 is cylindrical in configuration and is slidingly received by abore 92 through housing 88. Such slider 86 is manually displaceable by agrip 94 which is cylindrical in configuration and is provided with areduced diameter section 96 between a pair of handles 98. Reduceddiameter section 96 is slidingly received by a mating hole 100 throughslider 86 and a pair of longitudinal slots 102 in housing 88, as notedin FIG. 9. The width of slots 102 is similar to the diameter of reduceddiameter section 96 and the length of the slots is sutficient to permitfull retraction of piston 46 when slider 86 is displaced in housing 88.Provided at the end of one of the slots 102, adjacent the discharge endof cylinder 40, is a hole 104 which has the same diameter as the relatedone of the handles 98.

Thus, piston 46 may be releasably locked in the retracted position, topermit the loading of lubricant 32 into reservoir 48 or to release thepressure of the piston on the lubricant in the reservoir, by pulling ongrip 94 until the related one of the handles 98 is aligned with hole 104and then is pressed thereinto. The position of grip 94 along housing 88,when released therefrom, indicates the position of piston 46 in cylinder40 and therefore the amount of lubricant 32 in reservoir 48.

From the foregoing it is evident that lubricator 30 of the inventionassures that cases 34 are positively lubricated at all attitudes and inall operating conditions to which machine gun 12 may be subjected.Through the pressure applied by piston 46 to lubricant 32 in reservoir48 agitation of the lubricant, which might cause air bubbles to formtherein and cause improper discharge of the lubricant, is prevented.This pressure, too, assures discharge of lubricant 32 onto cases 34 atall attitudes of machine gun 12.

Also, through the use of negator type springs 62 a constant force isapplied to piston 46 throughout the length of its travel in cylinder 40so that each of the cases 34 is lubricated with the same amount oflubricant 32.

Moreover, through this invention the amount of lubricant 32 applied tocases 34 is adjustable by the addition or removal of shims 80 betweenapplicator 36 and housing 22. This varies the distance between the endsof pins 76 and slideways 26 and so varies the length of time thatplunger-valves 74 are held open by case 34 and the degree to which theyare opened.

Although a particular embodiment of the invention has been described indetail herein, it is evident that many variations may be devised withinthe spirit and scope thereof and the following claims are intended toinclude such variations.

I claim:

1. The combination comprising a cartridge with a case, a machine gun forfiring said cartridge, said machine gun having a receiver and a feedermechanism for delivering said cartridge to said receiver, a lubricant,and a lubricator for applying said lubricant to said cartridge at thecase thereof during displacement to said receiver, said lubricatorincluding a reservoir of variable capacity adapted to confine a variablesupply of said lubricant,

an applicator for applying said lubricant to said cartridge and meansfor transferring said lubricant from said reservoir to said applicatorat all variations in the supply of said lubricant in said reservoir andat all attitudes of said machine gun, said lubricator also including acylinder having a discharge end, a cap mounted on the discharge end ofsaid cylinder, a recess formed inside said cap, and a piston slidinglymounted in said cylinder to form said reservoir between said piston andsaid cap, said means including a variable spring device for applying tosaid piston a constant force towards said cap at all positions of saidpiston in said cylinder.

2. The combination as defined in claim 1 wherein said device includes ayoke mounted in said cylinder at the discharge end thereof, a pair ofdrums rotatingly mounted in said yoke, a spring of negator type wound oneach of said drums, a free end on each said spring fastened to saidpiston for transferring the constant force of said spring thereto andbores through said yoke for passage of said lubricant therethrough tosaid recess.

3. The combination as defined in claim 2 wherein said feeder mechanismincludes a feedway housing and slideways therein for slidinglysupporting said cartridge during displacement to said machine gun andsaid applicator is mounted on said feedway housing over said slideways,and including means in said applicator for applying a specific amount ofsaid lubricant onto said case while passing along said slideways.

4. The combination as defined in claim 3 wherein said means in saidapplicator includes a chamber for receiving said lubricant from saidreservoir, a pair of nozzles extending from chamber in the direction ofsaid slideways, a plunger-valve mounted in each said nozzle forreleasably blocking discharge of said lubricant therefrom, and a pinextending from each said plunger-valve for simultaneous contact by saidcase when passing along said slideways so as to be cammingly displacedthereby to release said lubricant for discharge onto said case.

5. The combination as defined in claim 4 and including means foradjusting the amount of said lubricant discharged onto said case.

6. The combination as defined in claim 4 and including means foradjusting the distance between said applicator and said feedway housingto regulate the position of said pin on said plunger-valve relative tosaid slideways for varying the time said plunger-valve is held open bysaid case and the degree to which said plunger-valve is opened.

7. The combination as defined in claim 4 wherein said lubricatorincludes a cable device attached to said piston for manual displacementaway from said cap and means for releasably holding said piston at aretracted position in said cylinder.

8. The combination as defined in claim 7 wherein said cable deviceincludes a slider, a housing mounted on said cylinder for slidinglyreceiving said slider, a cable connecting said slider to said piston, agrip mounted through said slider and extending through cooperating slotsin said housing in which said slider is mounted to provide means forslidingly displacing said slider in said housing and displacing saidpiston in said cylinder 'and for indicating the position of said pistontherein.

References Cited UNITED STATES PATENTS 1,073,298 9/1913 Smith 89-11,334,052 3/1920 Putnam 89-161 X 1,350,645 8/ 1920 Eickhoff. 1,396,83211/1921 Graham. 1,656,960 1/1928 Soncini 891 X SAJMUEL W. ENGLE, PrimaryExaminer.

